I/O

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 #include <cio/io.h> 

Functions
ssize_t	cio_read (int fd, void *buf, size_t bufsize)
ssize_t	cio_write (int fd, const void *buf, size_t bufsize)
ssize_t	cio_sendfile (int out_fd, int in_fd, off_t *offset, size_t count)

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Function Documentation

ssize_t cio_read	(	int	fd,
		void *	buf,
		size_t	bufsize
	)

Read from a file descriptor.

Parameters:

	fd	file descriptor
	buf	buffer
	bufsize	maximum number of bytes to read

Return values:

	>0	the number of bytes read
	0	on end-of-file
	-1	on error with errno set

Precondition:

fd should be in non-blocking mode

See also:

read(2)

ssize_t cio_sendfile	(	int	out_fd,
		int	in_fd,
		off_t *	offset,
		size_t	count
	)

Transfer data between file descriptors. If offset is not NULL, it will be updated according to the number of bytes transferred.

Parameters:

	out_fd	target file descriptor
	in_fd	source file descriptor
	offset	pointer to file offset or NULL
	count	maximum number of bytes to transfer

Return values:

	>=0	the number of bytes transferred
	-1	on error with errno set

Precondition:

fd should be in non-blocking mode

Note:

any restrictions imposed by the platform's sendfile() implementation apply also to this function

Bug:

if in_fd returns EAGAIN (and there is no other I/O going on), this function busyloops

See also:

sendfile(2)

ssize_t cio_write	(	int	fd,
		const void *	buf,
		size_t	bufsize
	)

Write to a file descriptor.

Parameters:

	fd	file descriptor
	buf	buffer
	bufsize	maximum number of bytes to write

Return values:

	>0	the number of bytes written
	0	on end-of-file
	-1	on error with errno set

Precondition:

fd should be in non-blocking mode

See also:

write(2)